Immunomodulatory, apoptotic and anti-proliferative potentials of sildenafil in Ehrlich ascites carcinoma murine model: In vivo and in silico insights.

Sildenafil is a potent phosphodiesterase-5 (PDE5) inhibitor that effectively inhibits cGMP and increases the strength of nitric oxide. PDE5 was overexpressed in several carcinomas, including breast cancer, which inhibited tumor growth and cell division. The current research aims to investigate the in vivo sildenafil's immunomodulatory and antineoplastic potentials against Ehrlich Ascites Carcinoma. This study looked at the effects of sildenafil mono-treatment and co-treatment with cisplatin; tumor cell count, viability and the inhibition rate were determined. Apoptosis, cell cycle distribution, alterations in tumor cells and splenocytes proliferation, changes in splenocytes immunophenotyping using flowcytometry, plasma levels of malondialdehyde (MDA), reduced glutathione (GSH), interferone (IFN)-γ, granzyme B, alanine aminotransferase (ALT), aspartate aminotransferase (AST), urea, creatinine and hematological alterations were detected. Additionally, docking study was conducted to get further insights on how Sildenafil exerts its activity. Sildenafil mono-treatment and co-treatment with cisplatin markedly reduced tumor cell count, viability, growth rate and proliferative capability accompanied by apoptosis enhancement and G0/G1 and sub G1 cells cycle arrest. Fortunately, sildenafil evoked efficient cellular immune response by increasing plasma levels of granzyme B and IFN-γ, proportion of splenic T cytotoxic (CD3+CD8+) and T helper (CD3+CD4+), accompanied by decrease in the proportion of splenic regulatory T cells. . Moreover, in silico data suggest LcK and MAPKs as the potential targets of sildenafil. Furthermore, sildenafil rebalanced the oxidant-antioxidant status by decreasing MDA and increasing GSH plasma levels. Sildenafil successfully retrieved various hematological values besides renal and hepatic functions in EAC-bearing animals. In conclusion, our results suggest that sildenafil could be potential safe anti-tumor agent with immuno-modulatory properties against Ehrlich ascites carcinoma.

Antitumor and immune-modulatory efficacy of dual-treatment based on levamisole and/or taurine in Ehrlich ascites carcinoma-bearing mice.

Many alternative and complementary therapies for cancer have been reported. The objective of the present work is to examine antitumor and immune-modulatory properties of dual-treatment based on levamisole (Lms) and/or taurine (Tau) in Ehrlich ascites carcinoma-bearing mice. In the current study, Lms (10 mg/kg; subcutaneously) and Tau (640 mg/kg; intragastrically) was administered alone or as a dual-treatment. Lms or Tau was administered in combination with cyclophosphamide (CTX) (100 mg/kg; intraperitoneal) in mice bearing Ehrlich ascites carcinoma. Treatment with CTX or (Lms plus Tau) significantly reduced the ascitic tumor cell count, percentage of tumor cell viability while elevated the tumor inhibition rate and apoptosis percentage compared to non-treated animals. Dual-treatment (Lms and CTX) or (Tau and CTX) significantly potentiated the reduction of the ascitic tumor cell count, viability and augmented the tumor inhibition rate and apoptosis percentage compared to CTX-treated mice. Dual-treatment of (Lms plus Tau), (Lms plus CTX) or (Tau plus CTX) altered splenocytes immunological profile of CD3+CD4+, CD3+CD8+, CD4+CD25+ and CD11b+Ly6G+ cells in order to achieve better immune surveillance against tumor cells. In conclusion, dual-treatments based on Lms and/or Tau are promising therapies for cancer, not only due to its abilities to induce apoptosis in the tumor cells and modulate the immune response against them, but also due to its capabilities to potentiate the chemotherapy anticancer efficacy and minimize its adverse effects.